1. Field of the Invention
This invention relates to data storage systems, such as disk drives, tape drives and the like. More particularly, the invention is directed to a new form of data storage system that does not rely on magnetic, optical or magneto-optical means to store and retrieve information.
2. Description of the Prior Art
By way of background, data storage systems such as disk drives and tape drives conventionally implement magnetic, optical or magneto-optical recording and playback techniques to store and retrieve information on a passive storage medium. Magnetic storage devices utilize magnetic domains on a magnetic storage medium to represent stored data. During data readback operations, a magneto-resistive read head senses changes in the magnetic moments of the magnetic domains and generates a readback signal corresponding to the recorded information. Optical storage devices utilize pits formed on an optical storage medium to represent stored data. During data readback operations, an optical read head directs a laser light beam onto the storage medium. When the pits are encountered, the phase of the reflected light changes and produces a readback signal corresponding to the recorded information. Magneto-optical storage devices utilize perpendicularly oriented magnetic domains on a magneto-optical storage medium to represent stored data. During data readback operations, a read head directs a laser light beam onto the storage medium. The magnetic domains on the medium rotate the polarization vector of the incident light beam upon reflection, thus producing a readback signal corresponding to the recorded information.
It is to new techniques for storing information that the present invention is directed. In particular, instead of employing conventional magnetic, optical and magneto-optical storage methods as described above, a data recording and playback system that relies on head-media physical (including contact) interactions is considered for use in a data storage system.